I am not sure if this is the same bug, but I have experienced similar WW bug in the past. What happens is that if you will be cc-ed by an NPC Mob (knock back, shield bashed etc) during WW transformation being activated, when animation plays, sometimes you will get in this "limbo" WW state when you have WW model and animation set, but the game treats you as non-ww. You can not cancel WW ulti, since WW can't use ultimate and you can not accumulate ulti points. You can not use WW skills (since game considers you non-ww), but also you can not use other skills since you have WW skills slotted (or game considers you to have your regular skills, but displays WW skill icons and WW don't have animation for non-ww skills so you can't use them).

Anyway, the only way to "fix" that state that I know of is to change zones (port to any other overland zone or IC or Cyro or one of your houses). Sometime re-loging will help but I am not sure if it works in instanced locations. It sucks that it happnes, but as far as I am aware, this bug is in the game since last WW overhaul update (so for a very long time).